Anomalous Second Magnetization Peak in 12442-Type RbCa2Fe4As4F2 Superconductors

The second magnetization peak(SMP) appears in most superconductors and is crucial for the understanding of vortex physics as well as the application. Although it is well known that the SMP is related to the type and quantity of disorder/defects, the mechanism has not been universally understood. We selected three stoichiometric superconducting RbCa₂Fe₄As₄F₂ single crystals with identical superconducting critical temperature T_c ～31 K and simi...     

Ba1-xKxFe2As2单晶(Tc=38.5K)磁通钉扎力与钉扎机理研究

铁基超导体是在2008年由Hosono发现的一种新型超导材料, 由于其具有上临界场高、各向异性小、临界电流密度大等优点, 在世界范围内引起了广泛关注. 以Ba_1-xK_xFe₂As₂为代表的FeAs-122系超导体具有结构简单、合成温度低、单晶容易制备等优点, 是物理学家和材料学家关注的焦点. 本工作在获得最优化掺杂的Ba_1-xK_xFe₂As₂单晶(T_c = 38.5 K)基础上, 通过分析其在不同磁场条件下电阻温度变化关系、不同温度条件下的磁滞回线等数据, 系统的研究了Ba_1-xK_xFe₂As₂单晶磁通钉扎力和磁通钉扎机理. 研究发现Ba_1-xK_xFe₂As₂超导体具有非常高的磁通钉扎势, 其中9 T的外场条件下, 其在H//c轴和H//ab面的钉扎势分别为5800 K和8100 K, 展示出良好的应用前景; 通过进一步分析发现, 其磁通钉扎机理应是由于晶格内部的小尺寸缺陷引起的电子平均自由程变化而导致的δl钉扎.     

Critical Current Density,Vortex Pinning,and Phase Diagram in the NaCl-Type Superconductors InTe1-xSex(x = 0, 0.1, 0.2)

Research of vortex properties in type-Ⅱ superconductors is of great importance for potential applications and fundamental physics. Here, we present a comprehensive study of the critical current density Jc, vortex pinning,and phase diagram of Na Cl-type In Te_1-x Se_x(x = 0, 0.1, 0.2) superconductors synthesized by high-pressure technique. Our studies reveal that the values of Jc calculated by the Bean model exceed 10⁴A/cm² in the In Te_1-x Se